IEM Rack Case Sizes: Depth, U Count and Road Case Choices

A rack case has two sizes that matter: how many rack units tall it is, and how deep its rails are. Most people count the units and forget the depth, then find the mixer sticks out the back.

The short answer

• Height: add up every unit in rack units (1U is 1.75 inches), then add room for power and spares.
• Depth: find your deepest unit, then buy a case whose rail depth clears it with room for the plugs behind it.
• Type: molded for a band that loads its own van, roto-molded for more abuse, shock-mount for trucks and touring.

Rack units: how tall the case is

Every 19-inch rack follows the same standard, EIA-310. One rack unit, written 1U, is 1.75 inches (44.45 mm) tall. Front panels are 19 inches wide, and the mounting holes on the rails sit 18 5/16 inches apart. That is why a 3U mixer from one brand fits in any case from another.

1. List every rack unit you own and its height: an X32 Rack is 3U, a Shure P10T is 1U, two half-rack transmitters share 1U.
2. Add a space for a power conditioner and one for a UPS if you carry one.
3. Add a vent panel above anything that runs warm.
4. Add two spare spaces. Racks grow.

Common case sizes are 2U, 4U, 6U, 8U, 10U and 12U. Round up to the next one.

Rack depth: the number people miss

EIA-310 sets the width and the hole spacing, but not the depth. Every case maker picks its own, and every piece of gear has its own. These are some published depths for common IEM rack gear:

• Shure P3T: 172 mm (6.8 in).
• Midas DL32: 9.5 in (241 mm).
• Behringer X32 Rack: 287 mm (11.3 in).
• Shure P10T: 343 mm (13.5 in).
• CyberPower OR1500LCDRM1U UPS: 396 mm (15.6 in).

Those are body depths. The XLR, power and antenna plugs on the back need room too, and a cable bent hard against the case lid is a cable that fails. Compare the deepest unit plus its plugs against the case’s rail depth, not its outside depth.

Gear that is light and shallow, like a half-rack transmitter, hangs fine from the front rails alone. A deep, heavy unit like a UPS should also be held at the back, so pick a case with rear rails if you carry one.

Road case types

• Molded plastic: light and cheap. A Gator GR-6L is a 6U molded case with front and rear rails and 19.25 inches of rackable depth, and weighs 14 lb empty.
• Roto-molded plastic: thicker walls for more knocks. The SKB 1SKB-R8U is an 8U roto-molded rack with front and rear rails, 17.6 inches deep rail to rail.
• Shock-mount: the rack floats inside the shell on shock absorbers so trucks and drops don’t reach the gear. A ProX XS-SLAM2X16U24 holds two 16U racks, 24 inches deep, on four shock mounts each, and weighs 255 lb empty.

Pick the lightest case that survives how you travel. For what the case adds to the total, see how much an IEM rack weighs.

A worked example

A four-piece rack with four P3T transmitters, a combiner, an X32 Rack, a power conditioner and a UPS adds up to eight rack units. The deepest unit is the UPS at 396 mm, about 15.6 inches, which fits inside the SKB 1SKB-R8U’s 17.6 inches of rail depth with about two inches to spare for plugs. That case works. A 6U case would not, and neither would any case under about 16 inches of rail depth.

IEM Rig places every unit at its real height and depth, so you can see what fits before you buy the case.

Sources

• RackSolutions, What is EIA-310: 1U is 1.75 in (44.45 mm), 19 in panels, 18 5/16 in hole spacing, depth not set by the standard
• Shure P3T listing: 43 × 198 × 172 mm, half rack
• B&H Midas DL32 listing: 19 × 9.5 × 5.4 in
• Behringer X32 Rack listing: 132 × 483 × 287 mm, 3U
• Shure PSM1000 specification sheet: P10T 483 × 343 × 44 mm
• CyberPower OR1500LCDRM1U spec sheet: 433 × 44 × 396 mm
• SKB 1SKB-R8U listing: 8U, roto-molded, 17.6 in rail to rail, 24 in exterior depth
• SKB rSeries rack range: roto-molded racks from 2U to 12U
• Gator GR-6L listing: 6U molded, front and rear rails, 19.25 in rackable depth, 14 lb
• ProX XS-SLAM2X16U24 product page: two 16U racks, 24 in deep, shock mounts, 255 lb